Matsushita Electric has developed Smart, a three-dimensional VLSI circuitry simulation system that analyses the device structure of semiconductor elements in three dimensions and outputs the result in graphic form; it is claimed to be more accurate than previous systems with a simulation error rate of less than 5%, and if it is run on supercomputer it reduces the processing time by factor of 20 compared with earlier systems; functions handled include processing the simulation of the distribution impurities, and of the flow of electric current, permitting analysis of design rule geometries down to 0.5 microns.